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From: "vanyacpp at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug analyzer/109570] New: detect fclose on unopened or NULL files
Date: Thu, 20 Apr 2023 13:33:46 +0000
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: analyzer
X-Bugzilla-Version: 14.0
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X-Bugzilla-Who: vanyacpp at gmail dot com
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109570

            Bug ID: 109570
           Summary: detect fclose on unopened or NULL files
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: analyzer
          Assignee: dmalcolm at gcc dot gnu.org
          Reporter: vanyacpp at gmail dot com
  Target Milestone: ---

While cleaning up one not particularly well written program I noticed this =
code
fragment:

FILE* file =3D fopen(...);
if (!file)
{
    fclose(file);
    return false;
}

Passing NULL to fclose is undefined behavior. Perhaps -fanalyzer could warn
about code like this?=